36 research outputs found
Impact abrasion resistance quantification of protective motorcycle gloves
The hands are often the first contact point with the road surface in a motorcycle crash. Wearing well designed protective gloves has been proven to significantly reduce the occurrence and severity of injuries to the hand. The European Standard for motorcycle protective gloves requires testing of component materials separately and does not consider the impact of abrasive surfaces on seems. This work aimed to develop a new method of testing of fully constructed gloves as worn by a rider in impact abrasion situations. It used previously published fall mechanics to understand the areas that may undergo impact abrasion. It defines the important zones for abrasion resistance and details ideal impact/measurement geometry for measurement on a Cambridge type abrasion tester. It proposes a method for the impact abrasion resistance of the palm, knuckles, wrist, outer side of the little finger and the tops of fingers. This information may be used for the quantification of fully manufactured gloves for standard certification or use in a rating system
Motorcycle clothing fabric burst failure during high speed impact with an abrasive surface
High energy is involved when a rider impacts a road surface in a crash. Rider speed, height of fall and road surface morphology all contribute to the level of initial impact energy. Impact can cause fabrics and seams of protective garments to burst rendering their protective value void. The Cambridge abrasion tester tests protective clothing with a fall height of 50mm and abrasive belt speed of 28km/hr, far below what can happen in a “high side” motorcycle crash at 100km/hr. This work addresses the mechanics of what occurs in the first few microseconds of an impact and provides insight into the effect that speed has on fabric burst. This work used a Cambridge impact abrasion test to evaluate two different protective motorcycle clothing fabrics (a denim and brushed fleecy fabric over a p-aramid protective liner). It measured their abrasion resistance at an abrasion speed of 28km/hr and standard impact height. It used a high speed camera to measure the impact displacement of the test head. Fabrics with high stretch were more prone to burst failure on initial impact. Fabric burst is caused by a high speed tensile stress between the fabric coupled with the abrasion surface and the inertia of the body dragging against it. Stretch fabrics are pushed into the abrasion surface for a longer period by the body before the tensile stress occurs so the coupling force is higher. If the transition to abrasion occurs early in the impact then a fabric is less likely to burst
Thermal Physiology and Developmental Plasticity of Pigmentation in the Harlequin Bug (Hemiptera: Pentatomidae)
Traits that promote the maintenance of body temperatures within an optimal range provide advantages to ectothermic species. Pigmentation plasticity is found in many insects and enhances thermoregulatory potential as increased melanization can result in greater heat retention. The thermal melanism hypothesis predicts that species with developmental plasticity will have darker pigmentation in colder environments, which can be an important adaptation for temperate species experiencing seasonal variation in climate. The harlequin bug (Murgantia histrionica, Hemiptera: Pentatomidae, Hahn 1834) is a widespread invasive crop pest with variable patterning where developmental plasticity in melanization could affect performance. To investigate the impact of temperature and photoperiod on melanization and size, nymphs were reared under two temperatures and two photoperiods simulating summer and fall seasons. The size and degree of melanization of adults were quantified using digital imagery. To assess the effect of coloration on the amount of heat absorption, we monitored the temperature of adults in a heating experiment. Overall, our results supported the thermal melanism hypothesis and temperature had a comparatively larger effect on coloration and size than photoperiod. When heated, the body temperature of individuals with darker pigmentation increased more relative to the ambient air temperature than individuals with lighter pigmentation. These results suggest that colder temperatures experienced late in the season can induce developmental plasticity for a phenotype that improves thermoregulation in this species. Our work highlights environmental signals and consequences for individual performance due to thermal melanism in a common invasive species, where capacity to respond to changing environments is likely contributing to its spread
Quantitative Factors Proposed to Influence the Prevalence of Canine Tick-Bourne Disease Agents in the United States
The Companion Animal Parasite Council hosted a meeting to identify quantifiable factors that can influence the prevalence of tick-borne disease agents among dogs in North America. This report summarizes the approach used and the factors identified for further analysis with mathematical models of canine exposure to tick-borne pathogens
Microarray patch delivery of un-adjuvanted influenza vaccine induces potent and broad-spectrum immune responses in a phase I clinical trial
Microarray patches (MAPs) offer the possibility of improved vaccine thermostability and dose-sparing potential as well as the potential to be safer, more acceptable, easier to use and more cost-effective for the administration of vaccines than injection by needle and syringe. Here, we report a phase I trial (ACTRN12618000112268/ U1111-1207-3550) using the Vaxxas high-density MAP (HD-MAP) to deliver a monovalent influenza vaccine to evaluate the safety, tolerability, and immunogenicity of lower doses of influenza vaccine delivered by MAPs. To the best of our knowledge, this is the first study determining dose reduction potential using MAPs in humans. Monovalent, split inactivated influenza virus vaccine containing A/Singapore/GP1908/ 2015 [H1N1] haemagglutinin (HA) was delivered by MAP into the volar forearm or upper arm, or given intramuscularly (IM) once. Participants (20 per group) received HD-MAPs delivering doses of 15, 10, 5, 2.5 or 0 µg of HA or an IM injection of quadrivalent influenza vaccine (QIV). In two subgroups, skin biopsies were taken on days 1 (pre-vaccination) and 4 for analysis of the cellular composition from the HD-MAP application sites. All laboratory investigators were blind to treatment and participant allocation. The primary objectives of the study were safety and tolerability. Secondary objectives included immunogenicity and dose de-escalation assessments of the influenza vaccine delivered by HD-MAP. Both objectives were assessed for up to 60 days post-vaccination.
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Quantitative Factors Proposed to Influence the Prevalence of Canine Tick-Borne Disease Agents in the United States
The Companion Animal Parasite Council hosted a meeting to identify quantifiable factors that can influence the prevalence of tick-borne disease agents among dogs in North America. This report summarizes the approach used and the factors identified for further analysis with mathematical models of canine exposure to tick-borne pathogens
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A national-scale assessment of climate change impacts on species: assessing the balance of risks and opportunities for multiple taxa
It is important for conservationists to be able to assess the risks that climate change poses to species, in order to inform decision making. Using standardised and repeatable methods, we present a national-scale assessment of the risks of range loss and opportunities for range expansion, that climate change could pose for over 3,000 plants and animals that occur in England. A basic risk assessment that compared projected future changes in potential range with recently observed changes classified 21% of species as being at high risk and 6% at medium risk of range loss under a B1 climate change scenario. A greater number of species were classified as having a medium (16%) or high (38%) opportunity to potentially expand their distribution. A more comprehensive assessment, incorporating additional ecological information, including potentially confounding and exacerbating factors, was applied to 402 species, of which 35 % were at risk of range loss and 42 % may expand their range extent. This study covers a temperate region with a significant proportion of species at their poleward range limit. The balance of risks and opportunities from climate change may be different elsewhere. The outcome of both risk assessments varied between taxonomic groups, with bryophytes and vascular plants containing the greatest proportion of species at risk from climate change. Upland habitats contained more species at risk than other habitats. Whilst the overall pattern was clear, confidence was generally low for individual assessments, with the exception of well-studied taxa such as birds. In response to climate change, nature conservation needs to plan for changing species distributions and increasing uncertainty of the future
Progression to AIDS in South Africa Is Associated with both Reverting and Compensatory Viral Mutations
We lack the understanding of why HIV-infected individuals in South Africa
progress to AIDS. We hypothesised that in end-stage disease there is a shifting
dynamic between T cell imposed immunity and viral immune escape, which, through
both compensatory and reverting viral mutations, results in increased viral
fitness, elevated plasma viral loads and disease progression. We explored how T
cell responses, viral adaptation and viral fitness inter-relate in South African
cohorts recruited from Bloemfontein, the Free State
(n = 278) and Durban, KwaZulu-Natal
(n = 775). Immune responses were measured by
γ-interferon ELISPOT assays. HLA-associated viral polymorphisms were
determined using phylogenetically corrected techniques, and viral replication
capacity (VRC) was measured by comparing the growth rate of gag-protease
recombinant viruses against recombinant NL4-3 viruses. We report that in
advanced disease (CD4 counts <100 cells/µl), T cell responses narrow,
with a relative decline in Gag-directed responses (p<0.0001). This is
associated with preserved selection pressure at specific viral amino acids
(e.g., the T242N polymorphism within the HLA-B*57/5801 restricted TW10
epitope), but with reversion at other sites (e.g., the T186S polymorphism within
the HLA-B*8101 restricted TL9 epitope), most notably in Gag and suggestive
of “immune relaxation”. The median VRC from patients with CD4 counts
<100 cells/µl was higher than from patients with CD4 counts ≥500
cells/µl (91.15% versus 85.19%,
p = 0.0004), potentially explaining the rise in viral load
associated with disease progression. Mutations at HIV Gag T186S and T242N
reduced VRC, however, in advanced disease only the T242N mutants demonstrated
increasing VRC, and were associated with compensatory mutations
(p = 0.013). These data provide novel insights into the
mechanisms of HIV disease progression in South Africa. Restoration of fitness
correlates with loss of viral control in late disease, with evidence for both
preserved and relaxed selection pressure across the HIV genome. Interventions
that maintain viral fitness costs could potentially slow progression
Environmental Temperature Affects Prevalence of Blood Parasites of Birds on an Elevation Gradient: Implications for Disease in a Warming Climate
Background: The rising global temperature is predicted to expand the distribution of vector-borne diseases both in latitude and altitude. Many host communities could be affected by increased prevalence of disease, heightening the risk of extinction for many already threatened species. To understand how host communities could be affected by changing parasite distributions, we need information on the distribution of parasites in relation to variables like temperature and rainfall that are predicted to be affected by climate change.\ud
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Methodology/Principal Findings: We determined relations between prevalence of blood parasites, temperature, and seasonal rainfall in a bird community of the Australian Wet Tropics along an elevation gradient. We used PCR screening to investigate the prevalence and lineage diversity of four genera of blood parasites (Plasmodium, Haemoproteus, Leucocytozoon and Trypanosoma) in 403 birds. The overall prevalence of the four genera of blood parasites was 32.3%, with Haemoproteus the predominant genus. A total of 48 unique lineages were detected. Independent of elevation, parasite prevalence was positively and strongly associated with annual temperature. Parasite prevalence was elevated during the dry season.\ud
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Conclusions/Significance: Low temperatures of the higher elevations can help to reduce both the development of avian haematozoa and the abundance of parasite vectors, and hence parasite prevalence. In contrast, high temperatures of the lowland areas provide an excellent environment for the development and transmission of haematozoa. We showed that rising temperatures are likely to lead to increased prevalence of parasites in birds, and may force shifts of bird distribution to higher elevations. We found that upland tropical areas are currently a low-disease habitat and their conservation should be given high priority in management plans under climate change
Basic science232. Certolizumab pegol prevents pro-inflammatory alterations in endothelial cell function
Background: Cardiovascular disease is a major comorbidity of rheumatoid arthritis (RA) and a leading cause of death. Chronic systemic inflammation involving tumour necrosis factor alpha (TNF) could contribute to endothelial activation and atherogenesis. A number of anti-TNF therapies are in current use for the treatment of RA, including certolizumab pegol (CZP), (Cimzia ®; UCB, Belgium). Anti-TNF therapy has been associated with reduced clinical cardiovascular disease risk and ameliorated vascular function in RA patients. However, the specific effects of TNF inhibitors on endothelial cell function are largely unknown. Our aim was to investigate the mechanisms underpinning CZP effects on TNF-activated human endothelial cells. Methods: Human aortic endothelial cells (HAoECs) were cultured in vitro and exposed to a) TNF alone, b) TNF plus CZP, or c) neither agent. Microarray analysis was used to examine the transcriptional profile of cells treated for 6 hrs and quantitative polymerase chain reaction (qPCR) analysed gene expression at 1, 3, 6 and 24 hrs. NF-κB localization and IκB degradation were investigated using immunocytochemistry, high content analysis and western blotting. Flow cytometry was conducted to detect microparticle release from HAoECs. Results: Transcriptional profiling revealed that while TNF alone had strong effects on endothelial gene expression, TNF and CZP in combination produced a global gene expression pattern similar to untreated control. The two most highly up-regulated genes in response to TNF treatment were adhesion molecules E-selectin and VCAM-1 (q 0.2 compared to control; p > 0.05 compared to TNF alone). The NF-κB pathway was confirmed as a downstream target of TNF-induced HAoEC activation, via nuclear translocation of NF-κB and degradation of IκB, effects which were abolished by treatment with CZP. In addition, flow cytometry detected an increased production of endothelial microparticles in TNF-activated HAoECs, which was prevented by treatment with CZP. Conclusions: We have found at a cellular level that a clinically available TNF inhibitor, CZP reduces the expression of adhesion molecule expression, and prevents TNF-induced activation of the NF-κB pathway. Furthermore, CZP prevents the production of microparticles by activated endothelial cells. This could be central to the prevention of inflammatory environments underlying these conditions and measurement of microparticles has potential as a novel prognostic marker for future cardiovascular events in this patient group. Disclosure statement: Y.A. received a research grant from UCB. I.B. received a research grant from UCB. S.H. received a research grant from UCB. All other authors have declared no conflicts of interes